Modificaciones en la cabeza del sujeto de las fugas de El clave bien temperado de Johan Sebastian Bach, Libro I BWV 846 A 869, Köthen 1722, Libro II BWV 870 A 893, Leipzig 1744

Abstract

In this collection, Bach presents resourses applied to some of the theme entries in the central and the end of the fughes, either in the role of subject or response, consisting in producing variations in the head, ie within three sounds initials. No changes are reported here applied to the whole theme as contrary motion, augmentation, reduction, rhythmic changes, and mutations in the initial and final tonal response, and shortening of the conclusive sector and changes in the last sounds. These changes are intended to highlight or hide the appearance of the theme and are classified according to rhythmic aspects, change in height and registration, ornamental variation and distribution of sounds in different voices. Finally, these changes are listed under the numerology and the proportions used by the author.